RC F teaser Brochure
05-13-14, 05:23 PM
#32
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Yeah, "racing torque" is all about maximum torque available up in the topmost rpm (hence, the peak horsepower keeps climbing and comes in close to the rev limiter). For example, Lexus LFA makes its peak horsepower at 8700 rpm (9000 rpm for NE) and even at 9500 rpm, it is still making over 90% of its peak torque.
RC-F fulfills that very nicely. The M4 engine is just a normal turbo engine that makes the major chunk of all its torque in the midrange and completely runs out of steam after 6000 rpm. That is why the "in-gear" (low speed, tall gear) acceleration of M4 would be good and also part-throttle it will feel very peppy in the midrange.
However, BMW marketing was defiant and wanted to really use the mantra of "race bred" so they gave it a completely unnecessary 7600 rpm redline when it should have been no more than 7000 rpm. They wanted to market it as "high-revving" so they made pistons that can handle the engine speed, but not designed to flow well at high rpms for usable power (being a turbo engine).
I hope all magazines shift M4 at 7600 rpm in RC-F comparisons so that the M4 turns in much slower numbers.
RC-F fulfills that very nicely. The M4 engine is just a normal turbo engine that makes the major chunk of all its torque in the midrange and completely runs out of steam after 6000 rpm. That is why the "in-gear" (low speed, tall gear) acceleration of M4 would be good and also part-throttle it will feel very peppy in the midrange.
However, BMW marketing was defiant and wanted to really use the mantra of "race bred" so they gave it a completely unnecessary 7600 rpm redline when it should have been no more than 7000 rpm. They wanted to market it as "high-revving" so they made pistons that can handle the engine speed, but not designed to flow well at high rpms for usable power (being a turbo engine).
I hope all magazines shift M4 at 7600 rpm in RC-F comparisons so that the M4 turns in much slower numbers.
05-13-14, 10:03 PM
#35
Lexus Test Driver
How did they get the 118 mph trap speed? I don't believe it has been tested yet. 
Anyway, even if the RC-F is only able to match the straight line speed of the M4, for me it is either RC-F or bust. I think RC-F will be dynamically a better handling car around the track since it has a dedicated chassis as opposed to the baseline chassis of M4 being the much criticized 3-series chassis. The engine also like you said is much more exciting in the RC-F.
Put it altogether with the Lexus reliability, quality and durability, it is a tough combination to beat.
Anyway, even if the RC-F is only able to match the straight line speed of the M4, for me it is either RC-F or bust. I think RC-F will be dynamically a better handling car around the track since it has a dedicated chassis as opposed to the baseline chassis of M4 being the much criticized 3-series chassis. The engine also like you said is much more exciting in the RC-F.
Put it altogether with the Lexus reliability, quality and durability, it is a tough combination to beat.
I don't think it'll beat the M4 in straightline speed though. Over on the bimmer forums they're saying the M4 is underrated and probably makes 455hp based on the 118mph trap speed and weight, and mostly cause I don't think Lexus will have launch control. The Carbon package can probably only drop 50 lbs from the RC F max, mostly from losing the moonroof. Still, I like the RC F powerplant better with it's 'unending acceleration' feeling.
05-13-14, 10:13 PM
#36
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How did they get the 118 mph trap speed? I don't believe it has been tested yet.
Anyway, even if the RC-F is only able to match the straight line speed of the M4, for me it is either RC-F or bust. I think RC-F will be dynamically a better handling car around the track since it has a dedicated chassis as opposed to the baseline chassis of M4 being the much criticized 3-series chassis. The engine also like you said is much more exciting in the RC-F.
Put it altogether with the Lexus reliability, quality and durability, it is a tough combination to beat.
Anyway, even if the RC-F is only able to match the straight line speed of the M4, for me it is either RC-F or bust. I think RC-F will be dynamically a better handling car around the track since it has a dedicated chassis as opposed to the baseline chassis of M4 being the much criticized 3-series chassis. The engine also like you said is much more exciting in the RC-F.
Put it altogether with the Lexus reliability, quality and durability, it is a tough combination to beat.
I think the RCF is more like the next gen M3, may not be the fastest a straightline, but touches all the right spots. It'll definitely be more interesting modded as well, the new M3/4 has an even smaller turbo than the 335i, so I don't see the top end problem being fixed easily with a tune.
05-13-14, 10:31 PM
#37
Lexus Test Driver
Some dude privately tested his M3: http://f80.bimmerpost.com/forums/sho...d.php?t=984354
I think the RCF is more like the next gen M3, may not be the fastest a straightline, but touches all the right spots. It'll definitely be more interesting modded as well, the new M3/4 has an even smaller turbo than the 335i, so I don't see the top end problem being fixed easily with a tune.
I think the RCF is more like the next gen M3, may not be the fastest a straightline, but touches all the right spots. It'll definitely be more interesting modded as well, the new M3/4 has an even smaller turbo than the 335i, so I don't see the top end problem being fixed easily with a tune.
BMW actually went through to great lengths in encrypting the ECU so tuning would be very difficult on the new M4.
Last edited by 05RollaXRS; 05-13-14 at 10:42 PM.
05-14-14, 05:17 AM
#38
thats the tradeoff you get doing turbos, if you want fast response and reduced lag you have to go with small turbos but that also means those small turbos cant provide enough boost at high rpms. Just the reverse if you want bigger turbos for better high end, youll have lag at the low end. F it, I want a V8 so you dont have to deal with that. Tune isnt going to fix a mechanical limitation, its going to need bigger turbos to fix the top end but thats going to mean more lag
05-14-14, 07:11 AM
#39
Lexus Test Driver
thats the tradeoff you get doing turbos, if you want fast response and reduced lag you have to go with small turbos but that also means those small turbos cant provide enough boost at high rpms. Just the reverse if you want bigger turbos for better high end, youll have lag at the low end. F it, I want a V8 so you dont have to deal with that. Tune isnt going to fix a mechanical limitation, its going to need bigger turbos to fix the top end but thats going to mean more lag
Last edited by 05RollaXRS; 05-14-14 at 08:05 AM.
05-26-14, 06:45 AM
#41
Lexus Champion
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